Generally, a refrigerator has a plurality of storage chambers for accommodating and keeping food frozen or refrigerated, and one surface of each storage chamber is opened to receive or take out the food. The plurality of storage chambers include a freezing chamber for keeping the food frozen and a refrigerating chamber for keeping the food refrigerated.
In the refrigerator, a refrigeration system in which a refrigerant is circulated is driven. The refrigeration system includes a compressor, a condenser, an expander and an evaporator. The evaporator may include a first evaporator which is provided at one side of the refrigerating chamber, and a second evaporator which is provided at one side of the freezing chamber.
Cold air stored in the refrigerating chamber is cooled while passing through the first evaporator, and the cooled air may be supplied to the refrigerating chamber again. Cold air stored in the freezing chamber is cooled while passing through the second evaporator, and the cooled air may be supplied to the freezing chamber again.
As described above, the conventional refrigerator is configured so that the plurality of storage chambers are independently cooled through separate evaporators.
In this connection, the applicant has got a patent on an invention (Korean Patent No. 10-1275184 registered on Jun. 10, 2013)
In a refrigeration system of the above-described patent, there are disclosed a compressor, a condenser, a refrigerant supply unit, an expander, a first evaporator and a second evaporator. It may be understood that the first and second evaporators are heat exchangers which are provided to independently cool separate storage chambers.
The refrigerant supply unit may be configured with a three-way valve, and a refrigerant introduced into the refrigerant supply unit may be guided to the first evaporator or the second evaporator.
That is, the above-described patent is characterized in that the refrigerant is selectively supplied to the first evaporator or the second evaporator, performs a cooling operation in one of the plurality of storage chambers, and stops the cooling operation in other storage chambers.
As described above, in the conventional refrigerator, the plurality storage chambers are not cooled at the same time, but one storage chamber and the other storage chamber are selectively or alternately cooled. In this case, the storage chamber in which the cooling operation is performed may be maintained within an appropriate range of temperature, but a temperature of the storage chamber in which the cooling operation is not performed is increased and is out of a normal range.
When the cooling operation of one storage chamber is required, and it is also detected that the temperature of the other storage chamber is out of the normal range, the cooling operation of the other storage chamber may not be immediately performed. That is, in a structure in which the storage chambers are independently cooled, the cold air may not be supplied to a proper place, and thus operation efficiency of the refrigerator is lowered.
Meanwhile, the conventional refrigerator includes a defrosting heater which is installed at each one side of the first and second evaporators to remove frost generated on the first or second evaporator. When the defrosting heater is driven, excessive power consumption occurs.